Mutants of the mini-F plasmid pML31 thermosensitive in replication.
AUTOR(ES)
Eichenlaub, R
RESUMO
Hydroxylamine mutagenesis was used for the induction of thermosensitive replication mutants of the mini-F plasmid pML31. Replication mutants were characterized by studying the segregation kinetics and the incorporation of [3H]-thymidine into plasmid deoxyribonucleic acid at the nonpermissive temperature. Based on these experiments two types of mutants could be distinguished. Mutants of type I are fast segregating with the kinetics expected if plasmid replication was blocked immediately. Double-label experiments showed a rapid shut-off of replication in these mutants at 42 degrees C. Mutants of type II segregate slower, showing only a partial inhibition of plasmid deoxyribonucleic acid synthesis at the nonpermissive temperature. The label incorporated at 42 degrees C was predominantly found in open circular plasmid molecules.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=218213Documentos Relacionados
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